A damping valve is used in, for example, a piston that constitutes a vehicle shock absorber. A damping valve is constituted by a piston and an annular leaf valve. A piston includes an annular outer peripheral seat, an inner peripheral seat provided on the inside of the outer peripheral seat, an annular window formed between the outer peripheral seat and the inner peripheral seat, and a port that communicates with the annular window. The annular leaf valve is laminated on the piston, and an inner peripheral side of the leaf valve is fixed to a piston rod and an outer peripheral portion of the leaf valve is seated/unseated on the outer peripheral seat.
The leaf valve is laminated between the outer peripheral seat and the inner peripheral seat. Normally, by making the height in the axial direction of the outer peripheral seat greater than the height in the axial direction of the inner peripheral seat, the leaf valve can be deflected in advance just by laminating and fixing the leaf valve on the piston. Thereby, a valve opening pressure of the leaf valve is set. A spacer is interposed between the inner peripheral seat and the leaf valve, and the outer diameter of the spacer is nearly the same as the outer diameter of the inner peripheral seat. Thereby, an initial deflection amount imparted to the leaf valve can be adjusted, and thus the opening valve pressure of the leaf valve can be adjusted (for example, refer to JP2000-55103A).
A leaf valve is generally constituted by laminating a plurality of thin annular plates, and thus a damping valve having such a leaf valve is made of numerous parts. When assembling such a damping valve, first, the piston, spacer, and leaf valve are assembled on a rod-shaped retaining pin, and then these parts are removed from the retaining needle and mounted on the piston rod. Therefore, the damping valve can be efficiently assembled (refer to JP2001-20990A).